diff --git a/plugins/in_elasticsearch/in_elasticsearch_bulk_prot.h b/plugins/in_elasticsearch/in_elasticsearch_bulk_prot.h
index 28acce9d5fd..3cdefa0467c 100644
--- a/plugins/in_elasticsearch/in_elasticsearch_bulk_prot.h
+++ b/plugins/in_elasticsearch/in_elasticsearch_bulk_prot.h
@@ -20,6 +20,8 @@
 #ifndef FLB_IN_ELASTICSEARCH_BULK_PROT
 #define FLB_IN_ELASTICSEARCH_BULK_PROT
 
+#include "in_elasticsearch_bulk_conn.h"
+
 #define ES_VERSION_RESPONSE_TEMPLATE \
     "{\"version\":{\"number\":\"%s\",\"build_flavor\":\"Fluent Bit OSS\"},\"tagline\":\"Fluent Bit's Bulk API compatible endpoint\"}"